RESUMO
Background. It has been described that the walls of the amebic cyst from Entamoeba invadens are composed mainly of chitin, a polysaccharide of amino-sugars. It is also know that the synthesis of this polysaccharide is closely related to the degradation of the intracellular glycogen in this organisms. Nevertheless, it is not know whether the intracellular glycogen is really the source of the glucose requirements for the synthesis of the cell wall. Methods. To determine the relationship between the wall cyst synthesis and glycogen degradation, it was considered to develop an in vitro culture cell system to label this polysaccharide with radioactive glucose. In this study, a system of 14C-glucose incorporation in axenic cultures of E. invaden was developed. The experiments in the study were carried out to recognize if an increase occurred in the 14C-glucose incorportation into ameba when the amount of the radioctivity used was increased, or whether this incorporation is a dependent metabolic stage. Results. The results showed that the amount of glucose incorportation reached similar values of 4.5 x 10-12 mmol per cell in both cases. A differente slope in the glucose kinetic incorporation between the cultures previously subjected to glucose depletion and the standard cultures was observed. Conclusions. This axenic method of radioactive glucose incorporation in Entamoeba invadens could facilitate the analysis on a greater scale of the metabolism of this nutrient